Composite wood panels and similar panels are produced by securing, usually with glue, at least two, and generally three or more, layers of relatively thin boards. Compared to solid wood boards, such composite wood panels have advantages. For example, composite wood panels can be produced having a desired surface area that is not limited by the diameter of the trunk of a tree. Basically, any limitations with regard to the size of the surface area of the composite panel arise only from problems in handling the panels. Furthermore, composite wood panels demonstrate superior strength properties compared to normal solid wood boards that are not glued because, by transverse gluing of the boards, the direction-dependent strength properties of wood can be partially compensated and, as a result, changes of board shape due to the influence of environmental factors, like moisture, can be kept within prescribed limits.
A disadvantage in the present production of such multilayered solid wood panels is that an excess amount of wood starting material must be used because the production process involves a large amount of wood waste. Accordingly, such composite wood panels are correspondingly much more expensive. For example, if thin initial boards are used to manufacture the multilayer composite panel, the squared timber must undergo more saw cuts to produce to these thin boards. Therefore, depending on the desired thickness of the initial thin board, the saw cuts produce a large amount of unusable sawdust, that can represent 25-40% of the amount of the initial wood.
This large amount of waste wood is avoided in the production of particle boards, wherein the wood is reduced to small particles that then are pressed into boards with the aid of a binder. The manufacture of particle boards permits significantly improved raw material utilization, but the strength properties and the surface qualities of particle boards do not favorably compare to those of wood itself. In addition, the manufacture of particle board requires the use of a large amount of binder, that in turn presents environmental and health problems because most binders contain formaldehyde.
Therefore, an important aspect of the present invention is to provide a method of preparing multilayered solid wood panels, and similar multilayer laminated products, wherein the initial raw material, like wood, can be utilized with significantly less waste generation than was possible in the previous conventional methods of preparing laminated products. In addition, the multilayered solid wood panels manufactured by the present method still possess qualities and properties that are comparable to or even better than the qualities and properties of composite wood panels made from boards produced by a sawing method. This aspect of the invention is achieved by providing thin wood boards from squared timber by a knife cut, and by securing the thin boards to one another in a particular manner as fully described below to provide a multilayered solid wood panel.